class X{
    Y y=new Y();//1

    public X(){//2
        System.out.print("X");
    }
}
class Y{
//
    public Y(){//3
        System.out.print("Y");
    }
}
public class chap12_4 extends X {
    Y y = new Y();//4
    public chap12_4() {//5
        System.out.print("Z");
    }
    public static void main(String[] args) {
        new chap12_4();
        System.out.println("===");
    }
}